Dependence of the Predicted Pair-Instability Supernova Rate on the Pop III Initial Mass Function

Abstract

Population III stars are a theoretical population of metal-free stars which formed during the first billion years after the Big Bang and ended the Cosmic Dark Ages. However, to date, Pop III stars have not been directly observed, as such our knowledge of this population is dependent on theoretical work. Upcoming observations provide us with the first opportunity to detect Pop III stars and their effects. This work focuses on the subset of Pop III stars that end in hyper-luminous Pair Instability Supernovae (PISN), which are within reach of direct detection by JWST. Coupling observed PISN rates to the astrophysics of the first stars requires a quantitative understanding of the dependence of PISN rates on the Pop III stellar initial mass function (IMF). We present results from a new semi-analytic model (SAM) which treats the slope of the Pop III IMF and the maximum mass of Pop III stars as free parameters.